GSM (Global System for Mobile Communications) is the technology that lets devices connect to the mobile network for calls, SMS, and data. In Arduino and embedded projects, a GSM module acts like a “cellphone for your circuit,” allowing your system to send alerts, receive commands, track locations, and communicate remotely without Wi-Fi. This makes GSM perfect for remote monitoring, security systems, automation, and field deployments where long-distance, reliable communication is needed. #Hajimer